The Brain Activation of Anxiety Disorders During Emotional Stimulations: A Coordinate-Based Activation Likelihood Estimation Meta-Analysis

Many studies have been analyzed the state of brain activation about anxiety under neuroimaging experiments with emotional stimuli. However, there is no meta-analysis to assess the commonality and specificity activation of different anxiety subtypes. Here, we used the activation likelihood estimation (ALE) to define the common and different activation between different subtypes of anxiety. A total of 29 functional magnetic resonance imaging (fMRI) studies revealed significantly increased bilateral amygdala, anterior cingulate gyrus, and parahippocampal gyrus activation in anxiety during emotional stimuli. Moreover, we observed the decreased activations in the posterior cingulate, lingual gyrus, and precuneus. In subanalyses of anxiety disorders, the increased activation of generalized anxiety and specific phobias are present in the left hippocampus and thalamus, respectively. Social anxiety and panic disorders showed increased activation in the parahippocampal gyrus, amygdala, thalamus, and insula. Social anxiety, generalized anxiety, and panic disorders displayed decreased activations in the fusiform gyrus, posterior cingulate, and specific phobias exhibited in the medial frontal gyrus. Although different anxiety showed dissimilar activations, the principal activations were observed in the limbic lobe, which might indicate the limbic circuit was a neural reflection of anxiety symptoms.

Tips for Effective Implementation of Virtual Reality Exposure Therapy in Phobias—A Systematic Review

Background: The high incidence of phobias and the limited accessibility of psychotherapy are the reasons for the search for alternative treatments that increase the availability of effective treatment. The use of virtual reality (VR) technology is an option with the potential to overcome the barriers in obtaining an effective treatment. VR exposure therapy (VRET) is based on a very similar rationale for in vivo exposure therapy. The study aimed to answer the question of how to perform exposure therapy in a virtual reality environment so that it is effective.Methods: A systematic review of the literature, using PRISMA guidelines, was performed. After analysis of 362 records, 11 research papers on agoraphobia, 28 papers on social phobia and 10 about specific phobias were selected for this review.Results: VRET in agoraphobia and social phobia is effective when performed from 8 to 12 sessions, on average once a week for at least 15 min. In turn, the treatment of specific phobias is effective even in the form of one longer session, lasting 45–180 min. Head mounted displays are an effective technology for VRET. Increasing the frequency of sessions and adding drug therapy may shorten the overall treatment duration. The effectiveness of VRET in phobias is greater without concomitant psychiatric comorbidity and on the condition of inducing and maintaining in the patient an experience of immersion in the VR environment. Long-term studies show a sustained effect of VRET in the treatment of phobias.Conclusion: A large number of studies on in VR exposure therapy in phobias allows for the formulation of some recommendations on how to perform VRET, enabling the effective treatment. The review also indicates the directions of further VRET research in the treatment of phobias.

Changes in Brain Activation through Cognitive-Behavioral Therapy with Exposure to Virtual Reality: A Neuroimaging Study of Specific Phobia

Background: Cognitive-behavioral therapy (CBT) with exposure is the treatment of choice for specific phobia. Virtual reality exposure therapy (VRET) has shown benefits for the treatment and prevention of the return of fear in specific phobias by addressing the therapeutic limitations of exposure to real images. Method: Thirty-one participants with specific phobias to small animals were included: 14 were treated with CBT + VRET (intervention group), and 17 were treated with CBT + exposure to real images (active control group). Participants’ scores in anxiety and phobia levels were measured at baseline, post-treatment, and 3-month follow-up, and brain activation was measured through functional magnetic resonance imaging (fMRI) baseline and post-treatment. Results: Both groups showed a significant decrease in anxiety and phobia scores after the therapy and were maintained until follow-up. There were no significant differences between both groups. Overall, fMRI tests showed a significant decrease in brain activity after treatment in some structures (e.g., prefrontal and frontal cortex) and other structures (e.g., precuneus) showed an increasing activity after therapy. However, structures such as the amygdala remained active in both groups. Conclusions: The efficacy of CBT + VRET was observed in the significant decrease in anxiety responses. However, the results of brain activity observed suggest that there was still a fear response in the brain, despite the significant decrease in subjective anxiety levels.

Snakes vs. Guns: A Systematic Review of Comparisons Between Phylogenetic and Ontogenetic Threats

The potential differences between phylogenetic threats (e.g., snakes) and ontogenetic threats (e.g., guns) can have a wide-ranging impact on a variety of theoretical and practical issues, from etiology of specific phobias to stimulus selection in psychophysiological studies, yet this line of research has not been systematically reviewed. Here, we summarize and synthesize findings from fear conditioning, illusory correlation, attention bias and neuroimaging studies that have compared these two types of threats to human survival. While a few brain imaging studies reveals preliminary evidence for different brain networks involved in the processing of phylogenetic and ontogenetic threats, attention bias studies tentatively show faster reaction time for modern threats, illusory correlation bias is evident for both types of threats, and fear conditioning studies are far from conclusive. The results of behavioral experiments, especially attention bias research, pose a challenge to established theories like biological preparedness and fear module. We discuss the findings in terms of other theories that might explain the same results and conclude with potential future directions.